Details of the model formulations and simulations are provided by [1]}. Briefly, the dry model [2]} approximates radiative transfer via Newtonian cooling, with the equilibrium temperature field that temperatures are relaxed toward being the forcing field from [3]} but maximizing at the north pole. The relaxation field is statically unstable, and a simple convective adjustment scheme relaxes temperatures of unstable columns toward a specified lapse rate at a fixed timescale of \(\gamma \Gamma _{d}\) , where \(\Gamma _{d}=g/\)  is the dry adiabatic lapse rate with \(c_p\)  the specific heat of dry air at constant pressure, and \(\gamma =0.7\)  mimics the stabilizing effects of latent heat release that would occur in a moist atmosphere (though the model is otherwise dry). Four simulations are performed, three with the \(\)  parameter that determines the horizontal temperature gradients of the forcing set to 1/15 and with the planetary rotation rate set to 0.25, 1, or 2\(\times \)  Earth's value, and another with \(=1/6\)  and Earth's rotation rate.
